Management of rice blast disease caused by Pyricularia oryzae through application of biocontrol agents and fungicides alone and in possible combinations

Rice blast caused by Pyricularia oryzae is considered as a major disease because of its wide geographic distribution and destructiveness under favourable conditions causing serious yield losses. The present study was undertaken to manage this disease under field conditions. Therefore, in vitro evaluation of biocontrol agents and fungicides against P. oryzae was done under laboratory conditions and a field experiment was conducted to evaluate the efficacy of bio-control agents viz., T. harzianum and T. viride and fungicides viz., tricyclazole and tebuconazole 50% + trifloxystrobin 25%, alone as well as in combinations against rice blast. In vitro studies revealed that among the biocontrol agents, maximum growth inhibition (43.99%) was recorded in T. harzianum. Among the fungicides, tricyclazole was the most effective in inhibiting the growth of P. oryzae at all concentrations. Under field conditions, combination of seed treatment with tricyclazole @ 2 g/kg of seed + two foliar sprays of tebuconazole 50% + trifloxystrobin 25% @ 0.1 per cent was the best in controlling the disease with the highest disease control (83.09 and 77.37%) and gave the highest grain yield 29.70 and 29.45 q/ha during Kharif 2018 and 2019, respectively.